We report a case of a 51-year-old man who received a cadaveric liver allograft for autoimmune and hepatopulmonary syndrome. The patient was admitted with symptoms of progressive vomiting and diarrhea 16 months after transplantation. Laboratory studies showed abnormal liver functions, and abdominal magnetic resonance imaging (MRI) showed a 76-mm heterogeneous mass in the liver. Histological examination showed a malignant lymphoid neoplasm with plasmablastic features. Plasmablastic lymphoma (PL) is rare in the post-transplantation period. To the best of our knowledge, only 25 well-documented cases of posttransplant PL, including ours, have been described.